1. Field of the Invention
The present invention relates to a semiconductor device in which a semiconductor element such as a memory element and/or a logic element, and a high frequency semiconductor element for handling high frequency signals are mounted on a common substrate.
2. Description of the Related Art
In recent years and continuing, there is a growing demand for higher integration of semiconductor elements such as electronic components in an electronic apparatus such as a mobile phone to realize miniaturization and technical improvements in the electronic apparatus.
In response to such a demand, a semiconductor device has been developed that accommodates plural semiconductor elements with differing functions (e.g., a memory element and/or a logic element such as a microprocessor) within a common container or package. Such a semiconductor device is referred to as a SiP (System in Package).
Also, with respect to the electronic apparatus, increased communication speed is being demanded for communicating with external units and/or apparatuses. Accordingly, a high frequency semiconductor element for handling high frequency signals within a frequency band of 0.1˜10 GHz, for example, may be provided within the container or package as is described above.
FIG. 1 is a diagram showing a structure of a mounting substrate accommodating a semiconductor device including semiconductor elements corresponding to a memory element and/or a logic element such as a microprocessor, and a semiconductor device including a high frequency semiconductor element.
In the illustrated example, a first semiconductor device 10 including semiconductor elements 21 and 25 corresponding to a memory element and/or a logic element, for example, and a second semiconductor device 40 including a high frequency semiconductor device 47 are mounted on one side of a motherboard (main electronic circuit substrate of an electronic apparatus) 55.
The first semiconductor device 10 includes a support substrate 11, semiconductor elements 21 and 25 that are mounted on one side of the support substrate 11, and external connection terminals 31 that are provided on the other side of the support substrate 11.
The support substrate 11 corresponds to a semiconductor element mounting substrate that includes via holes (filled with conductive material, but hereinafter referred to as via holes) 13 that penetrate through a base material 12 of the support substrate 11, wire connecting portions 14 and 15 that are provided at the upper ends of the via holes 13, and connection pads 16 and 17 that are provided at the lower ends of the via holes 13.
The semiconductor element 21 is mounted on the support substrate 11, and includes electrode pads 22 that are electrically connected to the wire connecting portions 14 of the support substrate 11 by wires 23.
The semiconductor element 25 is mounted on the support substrate 11, and includes electrode pads 26 that are electrically connected to the wire connecting portions 15 of the support substrate 11 by wires 28. The semiconductor elements 21 and 25 are sealed by resin 29 along with the wires 23 and 28.
The connection pads 16 and 17 are electrically connected to pads 57 or wiring 59 that are provided on the motherboard 55 via the external terminals 31 that are shaped into balls or bumps, for example.
It is noted that in one example, one of the semiconductors 21 and 25 may correspond to a logic element such as a microprocessor and the other one of the semiconductors 21 and 25 may correspond to a memory element such as a flash memory. In this case, the relative positioning of the logic element and the memory element (i.e., which of the semiconductor elements is placed on top of the other) may be determined depending on conditions such as the chip size (area) and the number of terminals required for realizing the functions and circuit configurations of the respective semiconductor elements.
The second semiconductor device 40 includes a support substrate 41, a high frequency semiconductor element 47 that is mounted on one side of the support substrate 41, and external connection terminals 53 that are provided on the other side of the support substrate 41.
The support substrate 41 corresponds to a semiconductor element mounting substrate that includes via holes 43 that penetrate through a base material 42 of the support substrate 41, wire connecting portions 44 that are provided at the upper ends of the via holes 43, and connection pads 45 that are provided at the lower ends of the via holes 43.
The high frequency semiconductor element 47, corresponding to a semiconductor element that is adapted to handle a high frequency analog signal having a frequency above 1 GHz, for example, is mounted on the support substrate 41, and includes electrode pads 48 that are electrically connected to the wire connecting portions 44 of the support substrate 41 by wires 49.
The high frequency semiconductor element 47 is sealed by resin 51 along with the wires 49. The connection pads 45 are connected to pads 58 or the wiring 59 provided on the motherboard 55 via external connection terminals 53 that are shaped into balls or bumps.
The wiring 59 provided on one side of the motherboard 55 realizes electrical connection between the first semiconductor device 10 and the second semiconductor device 40. For example, Japanese Laid-Open Patent Publication No. 2003-110084 discloses a technique relating to an arrangement as is described above.
In order to realize miniaturization and technical improvements in an electronic apparatus such as a mobile phone, a semiconductor element handling a high frequency signal is preferably mounted on a common substrate with a logic element and/or a memory element as is described above, rather than being provided as a separate semiconductor device.
However, as is known to persons skilled in the art, a high frequency semiconductor element is easily influenced by electromagnetic fields of other wiring and semiconductor elements located in the vicinity of the high frequency semiconductor element.
For example, in the example of FIG. 1, if the semiconductor elements 21 and 25 and the high frequency semiconductor element 47 are mounted on the mother board 55 as a common support substrate (interposer) and sealed together (packaged), interference may occur between a signal transmitted through the wiring/wire connected to the high frequency semiconductor element 47 and a signal transmitted through the wiring/wire connected to the semiconductor elements 21 or 25, and desired electric characteristics may not be obtained.
Accordingly, in the prior art, as is shown in FIG. 1, the semiconductor elements 21 and 25 and the high frequency semiconductor element 47 are mounted on the motherboard 55 as separate semiconductor devices 10 and 40, respectively.
However, when more than one sealed (packaged) semiconductor devices are mounted on one common support substrate as is described above, the packaging density of the support substrate may decrease, this being an obstacle to miniaturization of the electronic apparatus.
Also, when plural semiconductor devices other than those corresponding to the high frequency semiconductor element are separately formed on a support substrate and attempts are made to achieve desired electric characteristics for each of the semiconductor devices, the support substrate design may be complicated and the manufacturing cost of the electronic apparatus may be raised.
Further, in the above described structure, the length of the wiring connecting the high frequency semiconductor device to another semiconductor device (e.g., wiring 59 of FIG. 1) may be quite long so that a large transmission loss may be generated upon transmitting a high frequency signal.